by Patrick Linhardt
Hydronic Heating Wholesaler
THE PHONE CALL: It was strange for summer. A service manager was concerned about repeated automatic water feeder failure on the steam boiler at the home of one of his "good customers." These calls usually come into my office at the supply house in the milder parts of the heating season, not during the cooling season. But anytime the same component is replaced repeatedly under warranty, I get a little nervous and curious. We agreed to look at the system together.
I recognized the corner address he gave me. I'd never been inside but had often driven past and admired its stone walls, porches and turrets. Since I'm considered by some to be a steam geek, I wasn't disappointed by what we found inside, a wonderfully intact Trane vapor system from the 1920s. Sure, the boiler had been replaced a few times, but the radiator supply valves,
traps, main air vents and boiler return traps were still all there. Together they controlled the steam flow, air removal and condensate return in this classic two-pipe system. The geek in me was excited.
The nice elderly couple who lived there for the past 40 plus years told me how much they loved their "old steam heat." But during this past winter and spring, they had to keep draining the
action. Proudly I unzipped the cover and flopped it on the top of the boiler.
First, we did a quick tour of the basement to familiarize ourselves with the piping. We found the end of the mains and their vents. Then, back in the boiler room, we checked the book and agreed to use the flow chart "Boiler flooding" to start troubleshooting. All the usual suspects — dirty boiler, high pressure and near boiler piping — checked out OK. We zeroed in on, "Is wet return clean or clogged?" The Trane vapor system used a boiler return trap that has two check valves below it in the wet return. Sure enough, they looked original too.
Now, the wet return is the lowest part of the system and consequently accumulates the sediment, rust and junk of operation. This junk loves to build up around any obstructions, such as a check valve. These two valves had 75 years to get fouled up, since they didn't have any wrench marks and the original installer didn't provide any cleanouts in the wet return. It was looking less like a feeder problem. A clogged or slow wet return slows the condensate return, causing the feeder
to open. After a few cycles, the boiler is flooded with the return of the slowmoving condensate.
The system could be updated and the problem solved by repiping the wet return, this time without the boiler return trap and the check valves. The need for a boiler return trap ceased when the first gas-fired boiler was installed. Its job was taken over by the Pressuretrol or Vaporstat. Keep that set low enough, and gravity slides the water back into the boiler, as long as the pipe is clear.
We gave the owners a review of what we found. The couple understood that it was time to repipe the wet return and gave the OK to start. The service manager liked how my new book worked in the field and promised to order a few. My supply house didn't have to eat another part that wasn't defective and saved some money. The geek in me enjoyed the whole experience.
The follow-up
Like other diagnoses of old steam systems, this one was only partially correct. The check valves were found to be clogged but were passing some water. However, a 1-in. wet return traveling 70 ft. from a faraway corner of the basement was found to be 99.44% plugged. The condensate from that part of the house, maybe 25% of the system, was coming back extremely slowly, causing the feeder to flood the boiler. This wet return was even lower than the checks and consequently got the lion's share of the system buildup.
Patrick Linhardt is the sales manager at Aramac Supply in Cincinnati. His newly released book, "Linhardt's Field Guild to Steam Heating," can be ordered at www.steamupairoutwaterback.com or by calling 513/703-5347.
boiler and replacing the feeder. I dutifully followed them to the dining room to look at the radiator and noticed the nickel-plated finish on the 75-year-old supply valve. The steam inlet was at the top port on the radiator and the trap was at the bottom port on the
opposite end, just like it should be on a vapor system. The service manager and I excused ourselves from the couple and headed to the boiler room.
The troubleshoot
We didn't want to fire up the boiler while the A/C unit was whirling away. I had just published a book on steam heating, and my service manager friend wanted to see my new book in
Buderus joins fuel cell effort
BEND, ORE. — IdaTech has announced that German heating equipment manufacturer Buderus Heiztechnik GmbH, a company of the Bosch group, has joined RWE Fuel Cells in its program with IdaTech for the development of a commercial 5-kW combined heat and power (CHP) fuel cell system.
Earlier this year IdaTech announced a joint program with RWE Fuel Cells in the development and commercialization of CHP fuel cell systems for multi-unit housing and light commercial applications up to 50 kW.
Under this partnership, IdaTech will develop and manufacture the fuel cell systems. RWE Fuel Cells and Buderus
will integrate the fuel cells with heating systems to create a complete heat and power solution. RWE Fuel Cells and Buderus will test the fuel cell systems in the laboratory and in the field.
The first field trials with fully integrated fuel cell and heating systems are planned for installation in 2005.
IdaTech's fuel cell solutions are based on a modular design that supports the development of systems with a range of outputs up to 50 kW.
RWE Fuel Cells works on the development of products and services based on fuel cells as well as other small distributed energy plants, such as micro gas turbines and Stirling engines.